This invention generally relates to transformer coils. More particularly, the present invention provides a method of producing a encapsulated transformer coil with composite inner and outer layers.
Commonly assigned U.S. Pat. No. 6,221,297 to Lanoue et al. discloses a method of manufacturing transformer windings embedded in casting resin. A disposable mold is formed around support plates and is used as a winding mandrel. The disposable mold is formed from steel sheet material. After the coil is wound, another sheet of steel is applied to the outside. Epoxy is applied between the two sheets of steel and allowed to cure. Afterward, the steel sheets are removed, leaving an epoxy-encapsulated core.